From psychedelic pop to tropicália and kosmische experiments, Japanese musician, producer and artist Cornelius, known as Keigo Oyamada, is unafraid of turning his hand to any sound he can uncover. 

It means that over the past three decades, he’s forged his own sonic space within contemporary music. 

Taking the name of Cornelius from the chimpanzee in the original ‘Planet of the Apes’, Keigo initially emerged during the early nineties as part of Tokyo pop outfit before unveiling his own experimental solo career. 

1997’s ‘Fantasma’ was his breakthrough record, a release that endeared him to an international audience and saw him likened to Beck, Brian Wilson and the Beastie Boys. Almost 30 years later, Keigo is still endeavouring to unravel different musical sounds before restitching them to fit his own eclectic style. 

Latest LP ‘Refractions’ is his eighth solo album and as adventurous and playful as anything that has come before it. Featuring long-term collaborators and among many others, there’s an experimental palette pinned to a warm musicality only Keigo is capable of. Here, he shares how he started making music, how his past tracks have gone viral on TikTok and the making of this maximalist new record…

How did you find your way to music when starting out? Who were your biggest influences and inspirations?

My interest in music developed in stages. When I was very young, I loved music from special effects TV shows, anime, and commercials, followed by Japanese pop music known as Kayokyoku. Up until then, television had a huge influence on me.

In the upper grades of elementary school, I became interested in overseas rock and pop music. My older cousin had a massive collection of records, and I used to spend hours listening to them in his basement even when he wasn’t home – that was a major influence. By junior high, I started playing the guitar and formed a band with my friends.

By high school, I was joining and performing in numerous different bands with people both from school and outside of it. Most of them were cover bands, and I played across a wide variety of genres without sticking to just one: from The Jesus and Mary Chain and Echo & the Bunnymen, to Everything But the Girl and The Style Council, Minor Threat and 7 Seconds, Black Sabbath and Slayer, as well as Japanese pop songs, and even Toto and Journey. Around that time, I started getting interested in more niche, obscure music and actively searched for things to listen to. In Japan back then, we had a unique “record rental shop” culture where you could rent LPs cheaply, so I would borrow tonnes of records every week and tape them onto cassette cassettes. Because information was still scarce in Japan, music magazines and my friends were my biggest sources of inspiration.

You’re known as a groundbreaking artist behind the Shibuya-kei style – how did you tap into Western music and culture to inform your own music?

From the late 1980s to the early 1990s, there was no internet or digital environment like we have today, so import record shops, magazines, and books were our main sources of information. I grew up in Shibuya, so that kind of culture was a very familiar, everyday part of my environment. I absorbed not just music, but Western fashion, film, and other elements of culture as a whole.

Crucially, “Shibuya-kei” wasn’t a label we ever came up with ourselves – it was simply a term the media started using after the fact. Rather than just passively imitating Western culture, we used our own sensibilities to select, collage, and re-contextualize great records and art into new contexts. That natural, curatorial approach is ultimately what became known through the media as the Shibuya-kei style.

How did Flipper’s Guitar get together? And how did their success change your career? What was it like to be part of this influential group?

It actually started out as a five-piece band. I didn’t form it myself – I was invited to join. Later on, I invited a junior high school classmate to join, and as a result, the original members eventually left, leaving just the two of us from junior high to carry on.

As for “success”, I don’t know if we were truly successful, but we did manage to build a dedicated following of people who liked our music. Because of that, when I eventually started my solo career, people were interested in me right from the very beginning. 

At the time, I was only around twenty years old, just an immature kid, so being part of it all felt almost like taking a field trip to observe adult society.

‘Fantasma’ was released in 1997 to great acclaim. How do you feel about that record now?

1997 was a time when the echoes of Japan’s bubble economy were still lingering, and CD sales were at their absolute peak. In a way, it felt like the peak of post-war Japanese culture and ‘Fantasma’ feels very much like a product of that specific era.

Musically, the album mixes sampling and collage techniques inspired by hip-hop with live instrumentation and programming. Because copyright rules weren’t nearly as strict back then – especially in Japan – as they are today, we were able to make a record like that. 

Plus, I was still so young at the time, which is probably why it turned out to be such an intense, information-overloaded work. Looking back now, it feels like a snapshot of that unique period in time and my own youth.

What kind of musical equipment did you use to make the tracks on that album? Do you still use any of those items today?

At the time, I used equipment and sound modules like Akai samplers, digital tape recorders, and Roland JV synthesizers, but those digital tools are no longer used today. Equipment like that naturally evolved and was replaced by newer, more convenient technology. However, analogue gear like guitars and basses are things I still use just the same as back then.

Your nineties track ‘Typewrite Lesson’ has had a resurgence in interest via TikTok and Rosalia – how does it feel for the song to be in the spotlight again, especially as a b-side?

I was really surprised when the track suddenly started getting so many plays, and I honestly didn’t know that Rosalía was the catalyst for it. I love her music and visuals because they evoke a sense of both tradition and innovation, and I really appreciate her kitschy and humorous aesthetic, so it’s a huge honour.

On TikTok, though, it’s turned into this bizarre conspiracy theory claiming the song is a message directed at the hidden forces secretly ruling the world, which I find quite strange. As a phenomenon, it’s certainly interesting, but I don’t really feel any personal connection to that side of it.

Following my last two albums, ‘Mellow Waves’ and ‘MuChuMu’, which were more inward-looking, quiet, and ambient or singer-songwriter-oriented, I felt a desire to move in a more open direction. While turning inward can sharpen and refine your art, my mindset shifted toward opening outward and bringing in fresh, external elements. I think this was also influenced by the importance of connecting with others and the outside world at a time when division is such a major issue.

I wanted to clear away my usual self-imposed rules and embrace a non-self-contained approach—collaborating with outside artists and experimenting with AI – with the goal of letting the music venture into unexpected directions I couldn’t have planned on my own.

What inspired you to cover ‘Yumenemi’?  It was originally released in 1989 by one of Japan’s most iconic singer-songwriters, Yosui Inoue, and remains a cult Balearic classic – what is your connection with the song?

It was around before the pandemic, I believe. I stumbled upon ‘Pi Po Pa’, the opening track of the 1990 album ‘Handsome Boy’ (which features arrangement by Haruomi Hosono), when it appeared on my streaming recommendations, and I instantly fell in love with it. That led me to explore more of Yosui Inoue’s catalog on streaming services.

Yosui is a legendary singer-songwriter holding iconic, household-name status who has profoundly shaped the history of Japanese pop music, but for whatever reason, I had never really dived deeply into his work until then. Listening to his music reminded me of ‘Yumenemi’, from that same album, which was featured in commercials for the Nissan Cefiro starring Yosui himself. Those commercials were massive in Japan, and his famous catchphrase from them—”Ogenki desu ka?” (How are you?)—even became a nationwide pop-culture buzzword. When I revisited the song, I was struck by how incredible it truly is. It evokes the sensation of dreaming continuously from start to finish, and I had it on repeat while making my previous album. What makes it so compelling is its minimal structure combined with a psychedelic quality that floats between the boundaries of dream and reality. I was deeply drawn to those psychedelic elements, its unique worldview, and its rich acoustic textures.

You also worked with Sean Ono Lennon, Arto Lindsay, Shintaro Sakamoto, and Ganesh “Bid” Seshadri on the album – how did these collaborations come together? And what have you learned from working with these artists?

I have a long history with Sean Ono Lennon since our US debuts around the same time—from backing his Plastic Ono Band and label showcases to collaborating on the ‘Ghost in the Shell’ soundtrack. I deeply respect his character and talent, and on this album, he helped out extensively with the instrumentation.

My connection with goes back to my teens. After years apart, we reconnected at their live show in Japan, which led to me playing guitar for them during a subsequent tour. As our interactions grew during this album’s production, I knew I wanted them on it—it’s truly fate.

I’ve known since around 1998, when he spotted a billboard for ‘Fantasma’ in Shibuya featuring my Danelectro guitar, followed closely by seeing ‘Star Fruits’ on MTV. Since then, we’ve collaborated often, and I adore how his noisy, crazy guitar work coexists with a soft, floating aesthetic.

On top of that, I’ve known since his days in Yura Yura Teikoku. Being of a similar generation and having children the same age, we’ve been close friends for a long time, and I’ve always been a huge fan of his music. Ever since he disbanded his group, around the time I worked on the Salyu x salyu project, I frequently asked him to write lyrics. I have immense trust in his ability to capture the mood of society, abstract it, and transform it into addictive words. Their presence gave this record so many different directions and branches to explore. Having these musical heroes, long-time friends, and kindred spirits participate in this project makes me genuinely happy.

Aspiring creative people like musicians, artists or music producers could be reading this – do you have any advice for them?

What should I say here… I feel like nowadays, algorithms and trends change so quickly, and there’s so much pressure to constantly chase what’s popular or efficient. But my advice would be to stay true to what genuinely fascinates you, no matter how niche or weird it might seem. 

Follow your own curiosity deeply rather than trying to fit into a mold. If you keep pursuing the things that truly excite you, over time, that genuine passion becomes your own unique signature. Just keep trusting your own ears and instincts.

‘Refractions’ is out now via Eat Your Own Ears.